Journal Article
First report of Boeremia exigua causing leaf spot of tobacco (Nicotiana tabacum) in China
Tingting Xu; Pan Ma; Rubing Xu; Tom Hsiang; Junbin Huang; Lu Zheng; Yuan Fang; Yanyan Li
Australasian Plant Pathology · Vol. 54, Issue 3 · pp. 437-440 · 2025
Abstract
Tobacco ( Nicotiana tabacum L.) is an economically important crop, widely cultivated in China. Since 2021, a new leaf spot disease has been seen frequently in Enshi, Xiangyang, Yichang, and Shiyan, all in Hubei Province, China. Diseased leaves exhibiting roundish lesions with greenish-yellow edges were collected to determine the causal agent in summer 2022. After isolation, morphological characterization, and molecular identification (ITS, LSU, and TUB), the pathogen of the new tobacco leaf spot disease was identified as Boeremia exigua. Inoculation tests showed that B. exigua strains could cause this disease on detached tobacco leaves, and fungi were re-isolated with morphology identical to the inoculated strain, confirming Koch’s postulates. This is the first report of tobacco leaf spot caused by B. exigua worldwide.